Manufacture of insoles



, April 11, 1944. K. A. sTRn'TER MANUFACTURE OF INSOLES Fild- Nov. :5,1941 2 Shet-Sheet 2 Patented Apr. 11, 1944 UNITED O STATES ,PATEN'TOFFICE MANUFACTURE OF INSOLES I Karl A. Stritter, Nahant, Mass, assignorto United Shoe Machinery'Corporation, Flemington, N. 3., a corporationof New Jersey Application November 3, 1941, Serial No. 417,656

2 Claims. (c1. 36-44) This invention relates to improvements in themanufacture of insoles.

Reinforced insoles or insole units of a wellknown type have relativelyflexible foreparts but they are made relatively stiff and strong intheir heel and shank portions by the employment in each unit of ametallic shank stiffener and a heel and shank reinforcing piece offiberboard or the like which overlies and covers the shank stifiener andis secured by cement or otherwise to the insole. An insole unit of thistype usually comprises an insole body member of full insole length whichis died out or rounded to insole edge contour, and a heel and shankreinforcing and shank stiffener covering piece which is formed by aseparate die-cutting or roundin operation to correspond in edge contourwith that of the heel and shank portion of the body member. Th separatecutting operations involved in the making of the body members and thereinforcing pieces add substantially to the expense of manufacturingsuch insole units and further expense is involved inasmuch as it isnecessary to use considerable care to insure the subsequent as-'sembling and securing together of the parts with their rear and lateraledges in the desired accurate alinement.

One object of the present invention is to simplify and reduce the costof manufacture of reinforced insole units of the above-mentioned type.

With this object in view the present invention, as herein illustrated,provides an improved article of manufacture consisting of a compositesheet adapted to be cut into a plurality of insoles each of which has ashank stiffener covering piece already attached to it with its edges inexact registration with the corresponding edges of the body of theinsole, the covering piece, however, being attached throughout a portiononly or its full surface area so that part of the covering piece will befree from the adjacent body portion of the insole to permit thesubsequent insertion of a shank stiffener between the insole and thecovering piece. This composite sheet, in accord,-

ance with one illustrated construction, comprises a strip from whichinsole body portions of full insole length are to be cut, and a secondstrip from which the Covering pieces are to be cut,- the second stripbeing superimposed upon that part of the first strip from which theshank or shank and heel portions of insole bodies are to be cut andhaving its inner lateral margin only attached to the first strip. Theremainder of this covering piece strip is thus left unattached to thebody strip and consequently, in the insoles cut from'the sheet, thecovering pieces can be lifted so that the shank stiffeners can beinserted beneath them. Preferably the covering piece strip of the sheetis scored along a line located near its area of attachment to th otherstrip so that, in the insoles, the corresponding scored portions willfunction as hinges to facilitate the lifting or swinging of th coverinpieces away from the body strip. Preferably,

also, the insole body strip is of composite formation comprisingarelatively flexible portion from which the foreparts of the insoles areto be cut and a relatively stifi portion from which the shank or heeland shank portions of the insole body are to be cut, these two stripsbeing disposed in edge-to-edg relation in the same plane and havingtheir contiguous margins beveled or skived and'spliced together by acement joint.

The invention will be explained with reference to the accompanyingdrawings, in which Fig. 1 is a plan view of my improved composite sheet,dotted lines being employed in this view to indicate the locations ofthe cuts by means of which a plurality of fully length insoles are to becut from the sheet;

Fig. 2 is a sectional view taken along the line IIII of Fig. 1;

= section, of a composite sheet of another modified construction;

Fig. 5 is a perspective view of an insole cut from a composite sheet ofthe form shown in Figs. 1 and 2, showing the lower or outsole-facingside 1 of the insole;

Fig. 6 is a perspective view of an insole cut from a composite sheet ofthe form shown in Fig. 4, the insole being shown with its lower sideuppermost;

Fig. '7 is a longitudinal sectional View of the Fig. 10 is a bottom viewof the composite sheet shown in Figs. 8 and 9);

Fig. 11 is a View in longitudinal section of an insoles, the sheet beingof a width at least as great as the length of the insoles which are tobe produced and comprising two longitudinally extending zones A and B,the zone A being relatively flexible and consisting of a strip 16 ofmanufactured or composition material, for ex ample, felted wood fibersbound together with rubber, such material being commonly employed as asubstitute for leather, while the zone B is relatively stifi andcomprises superimposed and substantially coextensive strips or layers l8and 28, both of which are advantageously composed of fiberboard,leatherboard or the like. As shown, the inner lateral margin of thestrip I8 is skived or beveled and secured by a cement joint 22 (Fig. 2)to the correspondingly skived inner lateral margin of the strip l6. Itwill be seen that the strips l6 and I8 lie in the same plane andinasmuch as their contiguous edges are spliced and cemented togetherthey form a unitary ply or layer from which the body portions of fulllength insoles may be cut. The inner lateral margin of the strip 28 isalso skived and secured to the strip l6 of the body layer by a cementjoint 24 which is in line with the splice or joint 22. The layers orstrips l8 and 20, however, are left unsecured to one another from theirskived portions which are secured to the strip l6 to their outerextremities 25. To illustrate that the layers l8 and 20 of the compositesheet are entirely free one from the other except where they are joinedto the strip 16, the layer 20 is shown displaced somewhat from the layerl8 but actually these two layers will be disposed with their opposedsurfaces in contact where they are unattached. Preferably, the strip 20is scored or grooved on its outer side along a line 28 which extendslengthwise of the sheet approximately at the junction of the skivedmargin with the body portion of the strip so that in each insole cutfrom the sheet the covering piece, despite its stiffness, may be easilyseparated from the insole body by bending it about its scored portion.

The above-described composite sheet is adapted to be cut by dies orotherwise in the localities indicated by the dotted lines 30 in Fig. 1so as to produce a plurality of insoles, such as the insole 32 shown inFig. 5, each insole having a flexible forepart 34 of single-plyformation cut from zone A of the sheet and a two-ply heel and shankportion 36 cut from zone B of the sheet comprising two layers 38 and 40,both of which are preferably composed of relatively stiff material.Moreover, while the forward extremities of the layers 38 and 4Hconstituting the heel and shank portion of the insole are permanentlysecured at their forward extremities to the flexible forepart 34, asindicated at 42, the remaining portions of these layers are unattachedone to the other when the insoles are cut from the composite sheet. Inorder that the shank portion of the insole shall be sufficiently stiffand strong to afford adequate support forthe longitudinally archedportion of the foot, additional stiffening means may be inserted betweenthe layers 38 and 40. For this purpose a conventional metallic shankstiffener, such as that indicated at 44 in Fig. 7, is employed. Thelayers 38 and 40 are separated more or less from the positions in whichthey are shown in Fig. 5 to permit the insertion of the shank stiffenerand, as already indicated, such separation of the layers is facilitatedby bending the layer 40- away from the layer 38 about the line 46 (Fig.5) where that layer is scored. The score line insures that the layer 40will bend abruptly at the joint between it and the body of the insole sothat the shank stiffener can be located lengthwise of the insole mypositioning the front end of the shank stiffener in the apex of theangle between the layer 40 and the insole body, or, in other words,against the joint between the layer or covering piece 40 and the insole.As shown, the shank stiffener 44 may be secured to the layer 38 by meansof staples or tacks 41. Advantageously, the inner or opposed surfaces ofthe separated portions of the layers 38 and 40 are coated with cement,as indicated at 48 (Fig. 7), either before or after the shank stiffenerhas been applied, and subsequently the bent portion of the layer 40 isreplaced and pressed against the layer 38 until the two layers havebecome firmly attached together by the cement with the shank stiffener44 between them. Advantageously, the attaching pressure is applied bymeans of molds or forms suitably shaped to mold the shank portion of theinsole to last conforming shape. The layer 40 and the cement thus serveto retain the shank portion of the insole permanently in its molded formand the layer 40 supplements the reinforcing and stiffening action ofthe shank stiffener 44. The layer 40 also covers the shank stiffener 44and provides a continuous surface widthwise of the insole, at the loweror lasting side thereof, to which the upper of the shoe may be lastedand the outsole attached.

Instead of making my improved composite sheet with the skived lateralmargins of the layers I8 and 20 of zone B secured to opposite sides ofthe layer l6 of zone A, as shown in Fig. 2, the skived margins of thelayers I8 and 20 may-be secured to one another by a cement joint 50, asindicated in Fig. 3, in which case only one of the layers of zone B willbe cemented to zone A layer, for example the layer l8, the cement jointbeing indicated at 52. The layer 20 is shown as being scored at 28 as inthe sheet shown in Fig. 2.

Alternatively, the composite sheet may be constructed as illustrated inFig. 4 wherein the main or body layer I of the sheet is of integral orone piece formation throughout the full width of the sheet and the layer200 from which the covering pieces are to be out is composed of hardenedplastic or thermoplastic material, this layer being scored, as indicatedat 28, and :being secured at its inner lateral margin only to the mainor body layer by a cement joint 53, leaving the rest of the plasticlayer unsecured to the body layer. As shown, a thin facing of fabric 202asecured to the outer side of the plastic layer An insole cut from acomposite sheet constructed as illustrated by Fig. 4 is shown in Fig.

6 wherein the insole comprises a full length body layer 54 of one pieceintegral formation and a heel and shank reinforcing and shank piececovering layer 56, scored at 58 and faced on its outer side with afabric layer 59. The plastic material employed in the sheet shown inFig. 4

may be of an adhesive or bonding nature when activated either by heat orby means of a solvent so that in the insoles cut from the sheet it willbe unnecessary to employ cement to secure the covering piece to theinsole or the facing fabric to the covering piece inasmuch as thebonding together of these parts may be accomplished by merely pressingthem together while the plastic material is in a softened or activatedcondition. It may even be found unnecessary to employ a metallic shankstiffener between the layers in the heel and shank portion of the insolehaving a heel and shank piece made of plastic material, inasmuch as thismaterial itself, when hardened, may provide sufficient strength andstiffness in the heel and shank portions of the insole. The facingfabric '59 will provide an ideal surface at the lower side of the insolefor the cement attachment thereto of the upper materials and the outsoleof the shoe.

In Fig. i I have indicated a further modification in the construction ofmy improved composite sheet wherein zone B comprises three plies orlayers 28 i, 286 and 208, these plies being unattached to any otherportion of the sheet except along their inner lateral margins, and oneor more of the plies of zone B being preferably composed of materialwhich is stiffer than that of the ply of zone A. As shown, the ply 2534is secured by a spliced cement joint 2 ill to the insole forepartforming ply M2, the ply 236 is secured by a spliced cement joint 2 i itothe ply 2 l2, and the ply 208 is secured by a cement joint M6 to the ply265. In an insole cut from such a sheet the plies of zone B will besecured together as by means of cement in the molding of the insole sothat the heel and shank portion of the insole will permanently retainits molded shape. In order to provide for even greater strength shankreinforcing members. may be inserted between the adjacent plies of zoneB before these plies are fastened together. For example, a metallicshank stiffener may be introduced between plies 2M and 206 and a layeror coating of softened plastic material may be applied between plies 26Band 208, the plastic layer serving as a shank stiffening element afterbecoming hardened.

In making a sheet constructed as shown in Fig. 4; the ply 286 may bemade of plastic material and in an insole out from such a sheet theplastic layer may be softened, by means of a suitable solvent or bymeans of heat if the material is of a thermoplastic nature, before theinsole is molded, in which case the several layers or plies of the heeland shank portion of the insole will be secured together by the adhesiveproperties of the plastic layer without requiring the use of cement. Insuch an insole the hardened plas tic ply may provide sufficientstiffness but if desired a steel shank stiffener may be used between theplastic ply and one of the adjacent plies.

In order to provide for the cutting of insoles from composite stripswith less waste of stock than would result from the use of sheetsconstructed as already described, I may construct the sheets as shown inFigs. 8, 9 and 10 and reverse end-for-end the position of the cuttingdie prior to the making of each insole cut so that successive cuts willbe relatively disposed as indicated by the dotted lines 60 in Figs. 8and. 10. A sheet constructed as shown in Figs. 8 to 10 comprises arelatively stiff intermediate or middle zone C from which the heel andshank portions of the insoles are to be cut and relatively flexible sideor end zones D and E from which the foreparts of the insoles are to becut. Each of the end zones D and E consists of a. single ply strip 66offlexible insole material. As shown, the middle zone C is formed ofsuperimposed layers consisting of an insole body layer 62 and a coveringpiece layer 64, these layers being preferably composed of fiberboard orlike stiff material, although the layer 62 may be made of insolematerial and may be integral with the end zone layers or strips 66. Asshown in Fig. 9, the opposite lateral margins of the body layer 62 arebeveled or skived and secured by cement joints 68 and 10 to thecorrespondingly skived inner lateral margins of the.

forepart layers MS of zones D and E, respectively, while the oppositelateral margins of the covering piece layer 64 are secured by cementjoints 12 and M to the plies or strips 66 of zones D' and Erespectively. Inwardly of the joints l2 and i4, however, the coveringpiece layer 64 is left entirely unsecured to the rest of the compositesheet.

Preferably the layers 64 are scored along the lines 16 and 18.

When insoles are produced from a sheet such as that shown in Fig. 8 bycuts relatively disposed and located as indicated by the dotted linesfill,-

the layers constituting the heel and shank portions of the insoles,while secured at their forward extremities to the foreparts, will beunsecured to one another rearwardly of their forward extremitiesinasmuch as the rear extremities of the heel portions of the insole cutswill be spaced inwardly of the joints i2 and M. Consequently the layersof the heel and shank portions of each insole may be readily separatedto facilitate the insertion of a shank stiffener between them.

An insole cut from a sheet of the form exemplified by Fig. 8 is shown.in Fig. 11 wherein the forepart of the insole is indicated at 81], thebody of the heel and shank portion at 82, the heel and shank coveringpiece at 84, and the score line on the covering piece at 89. Thecovering piece 8 1 may be separated from the layer 32 to facilitate theinsertion of a shank stifiener by bending the a covering piecebackwardly about the portion The shank stifi-' weakened by the scoreline 85. ener having been positioned between the insole layers 82 and B4and stapled or otherwise secured to one or the other of them, theopposed surfaces of the layers will be coated with cement, unless theyhave been previously coated, and the covering piece layer will be laidback against the other layer and the two layers pressed together andmolded to last bottom conforming shape. Inasmuch as the joint betweenthe covering piece 84 and the forepart layer 89 is located fartherforward than the joint between the forepart layer and the heel and shankbody layer 82, as shown, the shank stiffener may be located with theforward portion overlying the latter joint, a condition which tends toprevent that joint from opening up or becoming weakened during thewearing of the shoe in which the insole is incorporated. This relativearrangement of the joints also enables the forward extremity of theshank stiffener to be located substantially at or even slightly forwardof the break line between the shank and forepart of the insole as isoften desirable. At the completion of the above-described operations areinforced insole unit will have been produced which will correspond inappearance and construction to that shown in Fig. '7 except as to therelative locations of the cement joints whereby the several layers ofthe unit are united.

.For use in making insoles with multi-ply heel and shank portions acomposite sheet may be formed with two single ply end zones and athreeply middle zone. Such a sheet may be formed, for example, by addingto the two plies of the middle zone of the sheet shown in Fig. 8 a thirdply and this third ply may be located at the side of the sheet oppositethat to which the ply 64 is applied, the third ply being unsecured tothe ply 64 and having its lateral margins secured to the end plies 66 bycement joints similar to and in line with the joints l2 and 14. Insolescut from such a sheet will have three-ply heel and shank portions andmay be reinforced by additional shank stiffening elements prior to themolding of the insoles as already described in connection with themaking of insoles from sheets of the type shown in Fig. 4

In various figures of the drawings the invention has been illustrated inits application to the cutting of insoles for use in shoes for the rightfoot of a wearer and it is to be understood that insoles for shoes forthe left foot can be cut by the use of another die which is properlyshaped to cut left insoles. However, a single die, for example a rightdie, may be used for cutting both right and left soles by practicing thesimple expedient of inverting the sheet after a right sole has been cuttherefrom. The right die may then be used upon the inverted sheet to cuta left insole, the insole being in an inverted position, however, at thetime it is cut. Moreover the composite sheets may be furnished in rightsand lefts, for example, one sheet may be adapted to yield right solesupon cutting by having the cover forming layer applied to its lower sidewhile another sheet may be adapted to yield left soles, when out by thesame die, by having the cover forming layer applied to its upper side.

The spliced cement joints between the strips constitutingthe middle zoneof the sheet and the strip or strips from which the insole foreparts areto be cut may be made as indicated at 94 and 96 in Fig, 13, wherein theinsole forepart forming strip 92 is beveled at the same angle at eachside to receive correspondingly beveled portions of the heel and shankpiece forming layers 88 and 90. The layers 88 and 90 are of the samethickness and may be made of the same material and, as shown, thecombined thickness of the layers 88 and 90 is the same as the thicknessof the layer 92. If the layers 88 and 90 are of the same material thecutting of both right 1. As an article of manufacture, a composite sheetadapted to be cut into a plurality of insoles with attached shankstiifener covering pieces, said sheet comprising a strip from which thebody portions of the insoles are to be out, and a second strip fromwhich said covering pieces are to be cut, said second strip beingdisposed in superimposed relation to that portion of the first stripfrom which the shank portions of the insoles are to be cut and havingits inner lateral margin beveled to a thin edge and said second striphaving said beveled margin only secured by a cement joint to said firststrip, and said second strip having a groove in its outer side extendingalong a line coincident with the inner extremity of said joint so thatthe cover piece of an insole cut from the composite sheet may be bentabruptly away from the other piece along the inner extremity of saidjoint to facilitate assembly of a shank stiffener with the insole.

2. A step product in the manufacture of reinforced insole unitscomprising a flexible insole forepart having its rear margin beveled toa thin edge, a stiff insole heel and shank part having its forwardmargin beveled to a thin edge, said parts having said beveled marginsdisposed in overlapping relation and secured together by a cement jointto form a composite insole body member, and a stiff heel and shankreinforcing and shank stiffener covering piece superimposed upon andcoextensive with said heel and shank part and having its forward marginbeveled to a thin edge, said beveled margin underlying the beveledmargins of said forepart and said heel and shank part and being securedby a cement joint to the beveled margin of one of said parts and beingentirely free of attachment to said part except at said joint, and saidreinforcing and covering piece having a groove extending across itsouter side in line with the rear extremities of the beveled margins ofsaid forepart and said heel and shank part.

KARL A. STRITTER.

